A mass attached to a spring is free to oscillate, with angular velocity $\omega,$ in a hortzontal plane without friction or damping. It is pulled to a distance $x_{0}$ and pushed towards the centre with a velocity $v_{ o }$ at time $t=0 .$ Determine the amplitude of the resulting oscillations in terms of the parameters $\omega, x_{0}$ and $v_{ o } .$ [Hint: Start with the equation $x=a \cos (\omega t+\theta)$ and note that the initial velocity is negative.]
The displacement equation for an oscillating mass is given by:
$x=A \cos (\omega t+\theta)$
Where,
$A$ is the amplitude $x$
is the displacement $\theta$
is the phase constant
Velocity, $v=\frac{d x}{d t}=-A \omega \sin (\omega t+\theta)$
At $t=0, x=x_{0}$
$A \cos \theta=x_{0} \ldots(i)$
And, $\frac{d x}{d t}=-v_{0}=A \omega \sin \theta$
$A \sin \theta=\frac{v_{0}}{\omega} \ldots(i i)$
Squaring and adding equations ( $i$ ) and ($ ii $), we get
$A^{2}\left(\cos ^{2} \theta+\sin ^{2} \theta\right)=x_{0}^{2}+\left(\frac{v_{0}^{2}}{\omega^{2}}\right)$
$\therefore A=\sqrt{x_{0}^{2}+\left(\frac{v_{0}}{\omega}\right)^{2}}$
Hence, the amplitude of the resulting oscillation is $\sqrt{x_{0}^{2}+\left(\frac{v_{0}}{\omega}\right)^{2}}$
Two particles $A$ and $B$ of equal masses are suspended from two massless springs of spring constants $K _{1}$ and $K _{2}$ respectively.If the maximum velocities during oscillations are equal, the ratio of the amplitude of $A$ and $B$ is
A mass $m$ is suspended by means of two coiled spring which have the same length in unstretched condition as in figure. Their force constant are $k_1$ and $k_2$ respectively. When set into vertical vibrations, the period will be
Two springs with negligible masses and force constant of $K_1 = 200\, Nm^{-1}$ and $K_2 = 160\, Nm^{-1}$ are attached to the block of mass $m = 10\, kg$ as shown in the figure. Initially the block is at rest, at the equilibrium position in which both springs are neither stretched nor compressed. At time $t = 0,$ a sharp impulse of $50\, Ns$ is given to the block with a hammer.
What provides the restoring force in the following cases ?
$(1)$ Compressed spring becomes force for oscillation.
$(2)$ Displacement of water in $U\,-$ tube,
$(3)$ Displacement of pendulum bob from mean position.
What is the period of small oscillations of the block of mass $m$ if the springs are ideal and pulleys are massless ?